High Light Output Power Density AlGaN-Based Deep Ultraviolet Micro-Light-Emitting Diodes

Compared with mercury lamps, AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) possess many distinctive advantages, including their being pollution-free, their long lifespan, their low operating voltage, their compact size, and their high-frequency modulation capability. However, poor light extraction efficiency (LEE) and inhomogeneous current spreading hinder their wider application in fields such as sterilization, disinfection, and non-line-of-sight solar-blind communication. To solve the issues above, high light output power (LOP) density AlGaN-based DUV micro-light-emitting diodes (Micro-LEDs) were fabricated in this work. The Micro-LED, with a peak emission wavelength of 281 nm, exhibited a 605% enhancement in peak LOP density of up to 77.1 W/cm2 at a high current density of 2.3 kA/cm2 compared to conventional DUV LEDs. Meanwhile, the LEE of the TE-polarized light of the Micro-LED was improved by 68%, which benefited from the small-size effect, and the peak external quantum efficiency (EQE) of the Micro-LED was enhanced by 24.6%. Moreover, the Micro-LED also showed a lower leakage current. This work provides an effective strategy to improve the efficiency characteristics of DUV Micro-LEDs.